Microdispensing pump

ABSTRACT

Several different features are provided for use with a pump, particularly a microdispensing pump. a first aspect of the subject invention, latch fingers are provided which coact with a stop member to yieldingly inhibit movement of an actuator of the pump to ensure sufficient momentum is provided to the pump for actuation. In a second aspect of the invention, an overcap is provided which defines an at least liquid-tight seal with the pump body at locations spaced from a nozzle of the pump to limit ingress of contaminants into the nozzle. In a third aspect, at least one protruding bead is provided in proximity to at least one edge of a label mounted to the pump body to restrict removal thereof. In a fourth aspect, at least one rib is provided in proximity to a dispensing cap to provide lateral stability thereto.

CROSS-REFERENCE TO RELATED APPLICATION:

This application claims priority of U.S. Provisional Application No.60/323,659, filed Sep. 20, 2001.

BACKGROUND OF THE INVENTION

Microdispensing pumps are known in the prior art, such as thosedisclosed in U.S. Pat. No. 5,881,956; WIPO PCT Published Application No.WO 01/14245; and related applications. The entire disclosures of thesereferences are incorporated by reference herein.

Although microdispensing pumps are known in the prior art, problemsstill exist with their operation and storage. For example, with amicrodispensing pump used in an ophthalmic application, ingress of dirtinto the pump's nozzle is a major concern. With prior art eye dropperbottle designs, a threaded overcap is typically provided which is formedto sufficiently thread onto a dropper bottle body to press against andform a tight mechanical seal against the dispensing aperture of thedropper bottle. However, with a microdispensing pump, such a design isnot practicable, because of the nozzle orientation (i.e., beingtransverse to the longitudinal axis of the pump body), as well as, thesimple fact that movement of the nozzle, vis-à-vis the dispensing cap,may result in inadvertent actuation of the pump. With eye dropperbottles, tight contact between an overcap and a dispensing aperture doesnot result in an inadvertent administration of fluid.

SUMMARY OF THE INVENTION

Various shortcomings associated with the prior art are addressed withthe subject invention. Different features of a microdispensing pump aredescribed herein which may be used in various combinations, or eachsingularly, and also may be used in various pump applications, notlimited to microdispensing pumps. Some of the features are particularlywell-suited for applications where accurate dosing is desired, such aswith ophthalmic applications.

In a variation of the first aspect of the subject invention, a pump isprovided including a plurality of cantilevered fingers; a piston isdisposed to slidably move at least partially within the fingers; and, astop member is at least partially disposed about the piston, the stopmember and the fingers being fixed to the pump body such that movementof the piston results in relative movement between the fingers and thestop member. In addition, the stop member is located to be contacted bythe fingers upon a predetermined extent of relative movement between thestop member and the fingers, with the fingers flexing upon contactingthe stop member such that the fingers yieldingly inhibit movement of thepiston. Accordingly, a predetermined amount of force is required toovercome the resistance provided by the fingers. In this manner,sufficient momentum must be required to actuate the pump to ensuredelivery of a proper dose, as disclosed in U.S. Pat. No. 5,881,956.

In a second aspect of the subject invention, a pump is provided havingan overcap formed to removably mount onto a pump body, the overcapdefining an at least liquid-tight seal with the pump body at locationsspaced from a nozzle on the pump body. In this manner, the overcap canbe used to restrict the introduction of dirt, debris and othercontaminants to the nozzle of the pump, with the pump not being in use.As such, the pump can be provided with a sufficiently proper seal whichcan withstand hazardous conditions, including those rigorous conditionsimposed by CCIT (container closure integrity testing).

In a third aspect of the subject invention, a pump is provided having atleast one bead protruding from a pump body in proximity to at least oneedge of a label mounted to the pump body. Particularly with labelshaving instructions and/or warnings, inadvertent or improper removal ofthe label is highly undesired. With the subject invention, removal ofthe label can be restricted.

In a fourth aspect of the subject invention, a pump is provided with apump body including a dispensing cap with a nozzle, the dispensing capbeing movable to actuate the pump. In one variation, at least onechannel is formed in the dispensing cap and at least one rib extendsinto each of the channels of the dispensing cap. The ribs each have asufficient length to at least extend substantially through therespective channel along full extent of movement of the dispensing cap.With the rib-channel interface, sideward movement of the dispensing capcan be limited. This is particularly desirable where straight-lineapplication of force to the dispensing cap is relied on to actuate thepump.

These and other features of the invention will be better understoodthrough a study of the following detailed description and accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are perspective views of a pump which may use one or moreaspects of the subject invention;

FIG. 3 is a partial cross-sectional view showing the latch fingers andribs of the subject invention;

FIG. 4 is a similar view to FIG. 3, with the dispensing cap being in adepressed condition;

FIG. 5 is a perspective view of a pump having an overcap mountedthereto;

FIG. 6 is a cross-sectional view of FIG. 5;

FIG. 7 is an enlarged sectional view of section 7 of FIG. 6;

FIG. 8 is a schematic showing a label disposed about the pump; and,

FIG. 9 is a partial cross-sectional view showing a lower portion of thelabel and protective beads disposed in proximity thereto.

DETAILED DESCRIPTION OF THE INVENTION:

With reference to FIGS. 1 and 2, a representative pump 10 is depicted,which may include one or more of the aspects of the subject invention.The pump 10 is formed for dispensing fluid, preferably ophthalmicmedication. As will be recognized by those skilled in the art, the pump10 may be formed with any configuration; for illustrative purposes, thepump 10 includes a pump body which may include a handle 12 (which mayhouse a fluid reservoir), a neck portion 14, a dispensing cap 16disposed within the neck portion 14, and a flip cap 18 hingedly mountedto the neck portion 14 via a hinge 20. A nozzle 21 is formed in thedispensing cap 16 to dispense the fluid upon actuation of the pump; theactuation preferably being achieved by depressing the dispensing cap 16and causing downward travel thereof. The pump 10 is preferably of alift-pump type formed in accordance with the teachings set forth in U.S.Pat. No. 5,881,956 and U.S. patent application Ser. No. 10/123,390, butmay also be of other pump types, such as a pre-compression type (formedin accordance with the teachings of WIPO PCT Published Application No.WO 01/14245), submersible pump type (such as that shown in WIPO PCTPublished Application No. WO 02/068317), and any other form known tothose skilled in the art. The inventive features described below areusable with the pump 10 and, as will be recognized by those skilled inthe art, in varying combinations or singularly. The disclosures of U.S.patent application Ser. No. 10/123,390 and WIPO PCT PublishedApplication No. WO 02/068317 are incorporated herein by reference.

Latch Fingers

As discussed in PCT Published Application No. WO 01/14245, and U.S. Pat.No. 5,881,956, the generation of sufficient momentum in actuating amicrodispensing pump will avoid partial dosing, as well as, ensuresufficient momentum for a dose is provided to be properly ejected from apump (and, therefore, properly administered).

With reference to FIGS. 3 and 4, flexible latch fingers 30 are providedwhich are circumferentially disposed about a poppet 32, having a stem 34and a head 36, and a slidable, tubular piston 38. A check valve element40 is disposed to control the fluid dosing from the pump 10 and iscontrolled by spring arms 42, as described in U.S. patent applicationSer. No. 10/123,390. In addition, the head 36 of the poppet 32 and thepiston 38 coact to form a shut-off valve, also, as described in U.S.patent application Ser. No. 10/123,390.

A tubular element 44 extends downwardly from the spring arms 42 whichterminates in an annular shoulder stop 46 that circumscribes the piston38. As such, the shoulder stop 46 is fixed to the dispensing cap 16 soas to move in concert therewith. Alternatively, the shoulder stop 46 canbe formed on any element fixed to the dispensing cap 16 or unitarilyformed with the dispensing cap 16.

To actuate the pump 10, downward force is applied to the dispensing cap16, resulting in downward movement of the shoulder stop 46, as well asthe piston 38. With such downward movement, the shoulder stop 46eventually comes into bearing engagement with the latch fingers 30,applying increasing downward force thereto commensurate with furthermovement of the shoulder stop 46. The latch fingers 30 restrict theability of the tubular element 44, and thus, the piston 38, from movingdownward. Upon a sufficient force being applied, as shown in FIG. 4, thelatch fingers 30 deflect outwardly with the shoulder stop 46 beinglocated between enlarged ends 48 of the latch fingers 30 and theshoulder stop 46. Thus, the piston 38 may travel its full extent andcause actuation of the pump 10—this actuation being achieved withsufficient momentum to ensure a proper dose of fluid is delivered. Themovement of the piston 38 causes a dose to be administered through thenozzle 21. The piston 38 may be used to generate pressure in fluid inthe pump 10 in any manner known to those skilled in the art to causedose administration and may be formed with any known configuration(i.e., not necessarily tubular as shown in the Figures). The latchfingers 30 will not yield until a sufficient force is applied to causethe latch fingers 30 to bend radially outwardly away from the piston 38.Preferably, the latch fingers 30 are cantilevered to a unitary component50 of the pump body of the pump 10.

As will be appreciated by those skilled in the art, the dispensing cap16 is an actuator of the pump 10. The subject invention can be used inother pump configurations to restrict movement of an actuator, where,for example, an actuator that is separate from its dispensing aperture(e.g., an actuator which is separate from a nozzle).

Preferably, the shoulder stop 46 is annular, but may also bediscontinuous. It is also preferred that the latch fingers 30 be evenlyspaced about the piston 38. The shoulder stop 46 can be formed withdiscontinuous limited surfaces for limited engagement with one or moreof the latch fingers 30.

The amount of resistance to downward movement of the shoulder stop 46(and, thus, to downward movement of the dispensing cap 16) generated bythe latch fingers 30 is a function of several factors, including, butnot limited to: the constituent material of the latch fingers 30; thephysical configuration of the latch fingers 30 (shape; inherent columnarstiffness; strength of cantilevered connection); and interaction betweenthe enlarged ends 48 and the shoulder stop 46 (angle of contact; shapes;degree of friction). If insufficient resistance is provided by the latchfingers 30, the latch fingers 30 will not ensure sufficient momentum isimparted to the pump 10 upon actuation. If, however, excessiveresistance is provided, the latch fingers 30 may buckle or be damaged(e.g., enlarged ends 48 could be scratched), resulting in inconsistentand unpredictable operation. It is preferred that the angle of contactbetween an end surface 45 of the shoulder stop 46 and top surfaces 47 ofthe latch fingers 30 (as represented by angle α in FIG. 3) be 10 degreesor less, more preferably 0 degrees. To obtain the angle α, the endsurface 45 and/or the top surfaces 47 may be tapered. It is alsopreferred that the surface finishes of the end surface 45 and the topsurfaces 47 be dissimilar. It is further preferred that the latchfingers 30 and the shoulder stop 46 be formed from dissimilar materials.For example, the shoulder stop 46 (which may be unitarily formed withthe tubular element 44) may be formed from polyethylene, whereas, thelatch fingers 30 (which may be formed unitarily with the component 50)may be formed from polypropylene, or vice versa.

It is also preferred that the latch fingers 30 be formed, for example,by injection molding, into a shape which does not correspond to itsundeflected state, as shown in FIG. 3. Rather, upon formation, the latchfingers 30 are bent or forced into the desired, undeflected state withthe constituent material of the latch fingers 30 not having been fullysolidified (e.g., upon being removed from a mold). In this manner, thelatch fingers 30 are biaxially stressed with the microscopic structurethereof being aligned to impart memory to the latch fingers 30themselves. This memory both encourages the latch fingers 30 to returnmore consistently to their undeflected position and to better resiststresses and strains of repeated operation. This same manufacturingtechnique is preferably used with the spring arms 42. It is preferredthat, in undeflected states, the latch fingers 30 bear against the outersurface of the piston 38, and the spring arms 42 bear against the checkvalve element 40.

Overcap

With reference to FIG. 5, an overcap 52 may be provided which mountsonto, and forms a seal with, the handle 12 of the pump body.Advantageously, the overcap 52 completely encompasses and protects thedispensing cap 16, and all components thereabout, including the nozzle21. With a seal being formed at locations spaced from the dispensing cap16 and the nozzle 21, the ingress of dirt and debris thereinto may beminimized. It is preferred that the overcap 52 form at least aliquid-tight, and, preferably, a fluid-tight seal with the pump body.

With reference to FIG. 6, the overcap 52 is preferably unitarily formedand has a cup shape. Edge 54 of the overcap 52 is placed into engagementwith the handle 12 upon the overcap 52 being mounted to the pump body ofthe pump 10. With reference to FIG. 7, the edge 54 is preferably formedto flare outwardly and to terminate in at least one retention bead 56.The shape of the edge 54 preferably matches that of the handle 12 of thepump body. At least two beads 58, 59 protrude from an external surfaceof the handle 12 of the pump body which are positioned to engage theovercap 52 above the large bead 56. The lower bead 58 is a retentionbead formed to interferently engage the retention bead 56 upon upwardmovement of the overcap 52 to inhibit removal of the overcap 52. In amounted position of the overcap 52, the retention bead 56 extendsinwardly of the lower bead 58.

The upper bead 59 is formed to interferently engage an inner surface 55of the overcap 52 to define a fluid-tight/liquid-tight seal. (Theoutline of the upper bead 59 is shown to overlap the edge 54 torepresent this interferent engagement.) In addition, the overcap 52 maybe formed to be stressed in a mounted position to enhance the seal'sintegrity such as by defining one or more contact points 61 between theinner surface 55 and the handle 12. The upper bead 59 and the contactpoints 61 define redundant seals in giving the pump 10/overcap 52assembly the liquid-tight/fluid-tight seal. The strength of the seal maybe adjusted for the pump's application; for example, where some gaspermeability may be desired, a fluid-tight seal is not appropriate.

The contact points 61 can be defined as a self-holding taper fit (e.g.,a Morse-taper type fit) which not only defines an at least liquid-tightseal, but also provides holding force for the overcap 52 to the pumpbody. With sufficient holding force and/or sealing integrity, theretention bead 56, the lower bead 58 and/or the upper bead 59 need notbe provided. It is preferred that the inner surface 55 and the handle 12define a taper angle in the range of 0°-7°, more preferably 1°-2.5°, atthe contact points 61 to define the self-holding taper fit.

It is preferred that the constituent material, preferably plastic, ofthe overcap 52 be resilient to allow the edge 54 to expand outwardlyupon mounting the overcap 52 so that the retention bead 56 may pass overthe beads 58, 59. The material, however, must have sufficient memory toensure sufficiently tight engagement of the bead 59 with the overcap 52.It is further preferred that cooperating shoulders 60 and 62 be formedon the overcap 52 and the handle 12 of the pump body, respectively, tolimit the downward movement of the overcap 52, thereby allowing forproper positioning thereof.

Beads for Protecting Label

Referring to FIG. 8, the pump 10 may be packaged with a clear orprinted-on label 64. Typically, the printed-on label 64 is shrunk onto(“shrink wrapped” onto) the pump 10. As shown in FIG. 8, the label 64preferably extends the full length of the pump 10/overcap 52 assembly toprovide an additional holding force for maintaining the overcap 52 onthe pump 10 and to indicate any tampering with the pump 10 prior toinitial use. For removal, a weakened portion 66, such as a tear linedefined by an array of perforations, is defined just below the overcap52, so that upon forcibly removing the overcap 52, the label 64 issevered into an upper portion 64 a and a lower portion 64 b.

It may be desirable to maintain the lower portion 64 b of the label 64on the pump 10, for aesthetic and/or marketing purposes. Additionally,the lower portion 64 b may contain instructions and other vitalinformation, such as warnings, relating to the fluid that is to bedispensed by the pump 10. Accordingly, to restrict the ability of a userin removing the lower portion 64 b of the label 64, protective beads 68and 70 (FIG. 9) are disposed in proximity to the upper and lower edgesof the lower portion 64 b. The protective beads 68 and 70 limit aperson's ability to pry or otherwise insert an object or a fingernailunder the lower portion 64 b and cause removal thereof. Preferably, theprotective beads 68 and 70 extend continuously about the pump 10 and arecoextensive with the lower portion 64 b. It is preferred that the upperprotective bead 68 be positioned adjacent to the weakened region 66 ofthe label 64 (when intact), and also in proximity to the edge 54 of theovercap 52 (FIG. 9).

As is readily apparent, optionally, one of the protective beads 68, 70may be provided. Also, the label 64 can be wholly formed to be disposedin proximity to one or both of the protective beads 68, 70 (e.g., formedonly as the lower portion 64 b). Also, the label 64, including any partthereof, can be affixed to the pump 10 in any manner known to thoseskilled in the art, including being adhered thereto.

Reduction of Dispensing Cap Float

With reference to FIGS. 3 and 4, the dispensing cap 16 is mounted tomove with the piston 38 to actuate the pump 10, such as via the tubularelement 44. Because of the slender construction of the piston 38 and thetubular element 44, and because these elements are movable, thedispensing cap 16 may have some lateral instability. Furthermore,because of manufacturing tolerances, a clearance C is between thedispensing cap 16 and the neck portion 14. Accordingly, the dispensingcap 16 may move laterally during actuation, for example under eccentricloading, and float into the clearance C. With the dispensing cap 16“floating” into the clearance C, downward force may be applied obliquelyto the tubular element 44 and/or to the piston 38, resulting in unevenloading on the latch fingers 30, on various seal faces, and/or othercomponents of the pump 10.

To minimize float, at least one rib 72 extends from a side wall 74(preferably, the side wall 74 is a portion of the neck portion 14) ofthe pump body of the pump 10 so as to engage or come into closeproximity with the dispensing cap 16. Preferably, a plurality ofcircumferentially spaced ribs 72 are utilized. With the dispensing cap16 being tapered (tapered skirt 75), as shown in FIGS. 3 and 4, lowerportions of the ribs 72 are in closer engagement with the dispensing cap16 than upper portions. With the ribs 72, float of the dispensing cap 16can be greatly minimized or even altogether eliminated, resulting ingenerally straight downward movement of the dispensing cap 16 duringactuation. The ribs 72 may engage an outer surface 73 of the dispensingcap 16 or, more preferably, extend into corresponding channels 76 formedin the dispensing cap 16. It is preferred that the ribs 72 havegenerally straight outer faces 78 (0 degrees of draft) and that aclearance of 0.001 to 0.005 inches be defined between the ribs 72 andthe associated opposing surface (the outer surface 73/the channels 76).

With reference to FIGS. 3 and 4, the dispensing cap 16 has a range ofmovement in actuating the pump 10 (FIG. 3 is an at-rest position of thedispensing cap 16; FIG. 4 is a depressed position of the cap 16). Theribs 72 are formed with sufficient length to at least extendsubstantially along the dispensing cap 16 for full extent of movement ofthe dispensing cap 16; where the channels 76 are provided, the ribs 72are formed with sufficient length to at least extend substantiallythrough the length of the respective channel 76 along full extent ofmovement of the dispensing cap 16. Preferably, the ribs 72 aresubstantially coextensive with the respective channels 76. As such, theribs 72 act to limit lateral movement of the dispensing cap 16throughout its range of movement.

As with previous aspects of the subject invention, this aspect can beused with various pump actuators and/or pump configurations. As afurther variation, the ribs 72 may be formed on the dispensing cap 16,and the channels 76, if used, on the side wall 74.

Various changes and modifications can be made to the present invention.It is intended that all such changes and modifications come within thescope of the invention as set forth in the following claims.

1-8. (canceled)
 9. A pump for dispensing fluid, said pump comprising: apump body having a nozzle; and, an overcap formed to removably mountonto said pump body, said overcap defining an at least liquid-tight sealwith said pump body at locations spaced from said nozzle.
 10. A pump asin claim 9, wherein said overcap is cup-shaped with an edge surroundingan open end thereof, said edge being formed with at least one retentionbead.
 11. A pump as in claim 10, wherein said pump body being formedwith at least one protruding pump body retention bead, wherein, withsaid overcap being mounted to said pump body, said pump body retentionbead being located within said overcap above said retention bead of saidovercap.
 12. A pump as in claim 11, wherein said pump body retentionbead is formed to interferently engage said retention bead of saidovercap upon upward movement of said overcap to inhibit removal of saidovercap.
 13. A pump as in claim 11, wherein said pump body being formedwith at least one protruding seal bead formed to interferently engagewith an inner surface of said overcap, with said overcap being mountedto said pump body.
 14. A pump as in claim 9, wherein said pump bodybeing formed with at least one protruding seal bead formed tointerferently engage with an inner surface of said overcap, with saidovercap being mounted to said pump body.
 15. A pump as in claim 9,wherein said pump body being formed with at least one protruding sealbead formed to interferently engage with an inner surface of saidovercap, with said overcap being mounted to said pump body.
 16. A pumpas in claim 9, wherein said pump body and said overcap are formed withcooperating shoulders to limit the downward movement of said overcaprelative to said pump body, whereby proper positioning of said overcaprelative to said pump body can be attained.
 17. A pump as in claim 9,wherein said at least liquid-tight seal is fluid-tight.
 18. A pump as inclaim 9, wherein a self-holding taper fit is defined between said pumpbody and an inner surface of said overcap.
 19. A pump for dispensingfluid, said pump comprising: a pump body; a label mounted about at leasta portion of said pump body; and, at least one bead protruding from saidpump body in proximity to at least one edge of said label.
 20. A pump asin claim 19, wherein said label is generally cylindrical having firstand second edges, said bead being coextensive with said first edge. 21.A pump as in claim 20, wherein at least two of said beads protrude fromsaid pump body, a second of said beads being located in proximity to,and coextensive with, said second edge.
 22. A pump as in claim 19,wherein said label is adherently affixed to said pump body.
 23. A pumpas in claim 19, wherein said label is shrunk onto said pump body.
 24. Apump for dispensing fluid, said pump comprising: a pump body including amovable dispensing cap with a nozzle, said dispensing cap being movableto actuate the pump, at least one channel being formed in saiddispensing cap, and at least one protruding rib extending into each ofsaid channels, each said rib having a sufficient length to at leastextend substantially through the length of said respective channel alongfull extent of movement of said dispensing cap.
 25. A pump as in claim24, wherein said dispensing cap includes a tapered skirt, said channelsbeing formed in said skirt.
 26. A pump as in claim 24, wherein each saidrib having a sufficient length to be at least substantially coextensivewith said respective channels along full extent of movement of saiddispensing cap. 27-35. (canceled)